The most recent economy trend in terms of power generation is directed towards renewable energy sources, saving the environment and capable of insuring a certain extent of energy independence for its consumers. One of the most significant, perspective and still unrealized sources is the reactive power. Technology of reactive power conversion into a useful energy that may be conveniently used by industrial and commercial facilities hasn't existed until now. This new technology will let to utilize the reactive power as a primary energy source and to convert it into a standard AC voltage for its farther use by different consumers.
Reactive power is considered to be an extremely negative phenomenon. Huge resources are being wasted to withstand the reactive power in power lines today. Significant efforts are being made as well to control and compensate the reactive power in power transmission and distribution systems consist of generating facilities, nets and consumers.
The level of the reactive power problem could be illustrated on an example of yesteryears three-phase devices. Up to three power stations were being used to supply merely ten enterprises those days. A sudden surge of power, increased standard 380 V voltage to 450-600 Volts, forcing electric machines to exceed their ability, which caused overloading of generating facilities on power stations and as a result, were disconnected from an overstrain or just were destroyed. It was an action of mighty reactive power.
It appears the reactive power has the same nature, as an active electric power, but arising from a resonance of inductance together with electric capacitance in the power network system, and is always directed back from consumers to their power station generators i.e. contrary to a working current from generators. It causes networks overheating and huge additional quantities of fuel wasting for its compensation.
Under the assumption of a great majority of engineers, reactive power is scooped from a magnetic field of the Earth and electric potential of its atmosphere.
Nikola Tesla was possibly the first who utilized reactive power in its useful purposes. It rotated an electromotor of his famous electro mobile, but principal schemes of this unit do not exist and we can only make assumptions
There is another example of a reactive power usage in practice. Dr. Vachaev (Russia) conducted his researches from 1960-70. He tested a water deep cleaning and treatment device with extraction of various substances from water suspension. His device had an extremely simple design. 220 Volt was applied to the scheme as indicated in FIG. 1. The current travelled through additional resistance R 2 to transformer TR 5 connected with a capacity C 4 (180-200 uF) and farther to a tubular sparking gap TD 3 immersed in a water. A tubular sparking gap was covered by a coil being fed with a direct current (not shown on the scheme). A small fireball discharge appeared at arch ignition in the gap, and powerful electromagnetic oscillations with about 30 MHz frequency occurred in the device. A strong reactive current arose in the transformer-condenser contour. The resistance R 2 served for limitation of this reactive current. As the key SW 1 was switched on load LR 6, the given contour became a source of a current itself and simultaneously made a self-supporting system for a significant period of time. But this design was limited in its constant generating ability by applied transformer with its iron core.
A Tesla air-core resonant type transformer invented by Nicola Tesla around 1891, shown schematically in FIG. 2, is effective, reliable and cost effective generator of high-voltage and high-frequency electromagnetic oscillations, which can be successfully used for exciting the system with a reactive power.
A Tesla coil type transformer (Tesla transformer) consists of a driving generator, a primary driving oscillating resonant circuit (primary coil) 7 and a secondary exciting oscillating resonant circuit (secondary coil) 8. The driving generator is intended for producing electric current oscillations to make the emitting secondary coil 8 to emit the electromagnetic radiation.
Typical Tesla transformer spark gap type driving generator comprises a high-voltage supplying transformer 9. The output of supplying transformer is rectified by a full wave bridge 10. Tesla transformer primary coil 7, a spark gap 11 and a high-voltage capacitor 12 are connected in series. The primary coil 7 is loosely electromagnetically coupled with the secondary coil 8, in the absence of a ferromagnetic core through mutual inductance. A discharge needle 13 is connected to the end of the secondary coil winding wire and is mounted on its top for a discharge corona creation purpose. Another end of the secondary coil winding wire is grounded.
Tesla transformer can have a spark gap, a transistor or a vacuum tube driving generator type.